A Study on Effective Amplification Gain in Cochlea Dead Region with Word Recognition Score

When the cochlea in the inner ear hair cell has functional problems, a sensorineural hearing loss (SNHL) occurs, and we called ‘cochlea dead region’. Cochlea dead region is that no (or very few) functioning in inner hair cell or neurons. In this paper, we tested word recognition score (WRS) to know an effective amplification of hearing aids with different location of dead region and gain (dB). The test signal was mixed with white and babble noise (SNR = 0 dB) for eight people who had normal hearing ability. We divided three conditions by location of dead region in low, middle and high frequency. Low frequency dead region was defined under 1100Hz in frequency. Middle frequency dead region was between 1350Hz and 2700Hz. High frequency dead region was over 3100Hz. In addition, gain was various such as 6 dB, 11.5 dB and 14.5 dB in each dead region. The results were different by locations and gains of dead region. Firstly, the result of WRS with middle frequency and high frequency dead region were higher than low frequency dead region. Secondly, the result of WRS was high score, when low gain in low frequency dead region, high gain in middle and high frequency dead region.